Manufacture of artificial wool



Aug. 25, 1942. L L

MANUFACTURE OF ARTIFICIAL WOOL Filed July 24, 1959 mum llhlll PatentedAug. 25, 1942 MANUFACTURE OF ARTIFICIAL WOOL Anton Lely, Velp,Netherlands, assignor to American Enka Corporation, Enka, N. 0., acorporation of Delaware Application July 24, 1939, Serial No. 286,283 InGermany August 8, 1938 2 Claims.

The present invention relates to the manufacture of artificial wool-likefibers prepared from casein solutions and more particularly to theproduction of casein yarns that closely simulate the appearance ofnatural wool.

When comparing natural wool with so-called casein wool produced understandard conditions, it has been determined that the natural product, asdistinguished from the synthetic yarn, has an inherent curl or crinklewhich offers better felting properties and produces a more voluminousand fluffy yarn.

It has now been found that it is possible to impart to casein fibers acurl corresponding to that of natural wool. Such results have beeneifected by rapidly stretching wet casein fibers and suddenly releasingthe tension thereon. The thus treated fibers display a peculiar finecurl corresponding to that of merino wool.

It is, therefore, the object of the present invention to manufacturecasein yarns that more closely resemble natural wool than any artificialproduct heretofore produced.

The invention further contemplates the provision of several methods forimparting a definite and accentuated curl or crinkle to casein fibers.

Another object of this invention involves the simultaneous production ofa number of casein fibers associated to form a cable and its subsequenttreatment to form a staple fiber having an improved curl or crinkle.

Essentially, this invention contemplates utilizing the inherentelasticity in fibers, slivers, cables and the like, prepared from caseinsolutions; and the process, broadly, consists of suddenly stretching thefilaments or fibers, and then quickly re-.

leasing the tension. This step may be carried out during any of themanufacturing operations, but is preferably conducted after the fibershave been subjected to a hardening treatment, for example, with aformaldehyde solution. Regardless of the stage at which the stretch isapplied, the fibers must be in a wet or moist condition.

In practicing the invention, the moist casein fibers are subjected to asudden high tension so that they are stretched, for example, from 20% to40%. Such stretching and immediate contraction may take place in anysuitable apparatus, such as that shown in the single figure of drawingwherein the fibers l, after extrusion from spinneret 2 into a spin bath3, are led through a formaldehyde hardening bath 3a and are stretchedbetween two successive pairs of rollers d, ta and 5, 5a in which thedistance D decreased periodically or non-periodically. Rollers I and 4aare mounted on shafts 6 and 6a which may be journaled in any suitableway, not shown. The said two rollers are caused to rotate in thedirection indicated by the arrows by any conventional driving means, notshown. Rollers 5 and 5a are similarly provided with shafts i and la,respectively. Rollers 8 and 5 serve to drive belts B and 9 which in turnare passed around guide pulleys l0 and Ii, respectively. Belts 8 and 9,during their upper path of travel, provide a horizontal moving surfacefor continuously carrying the fibers I between the successive pairs ofrollers. The distance D between pairs of rollers 4, la and 5, 5a isincreased and decreased by operation of cam l2 driven by shaft l3 andacting through link It pivoted at l5 to a bar It connecting shafts 1, laand the similar shaft for pulley H and acting as a jour nal therefor.The entire roller assembly 5 and 5a is mounted for reciprocatingmovement in a table H. A cutter l8 operates in synchronism with the caml2 whereby the fibers i may be cut at the point of greatest stretch. Thesupporting belts 8 and 9 are conventional as well as the driving camarrangement.

It is also possible to guide and keep the cables taut through successivepairs of rollers which are maintained ata constant distance and use ahammer stroke arrangement for striking a section of the cable betweenthe rollers at periodic or non-periodic intervals.

As indicated, if it is desired to produce staple fiber, the moist andsuitable hardened bundle of fibers produced from the simultaneousextrusion and treatment of a collected cable are suddenly stretched andsubjected to staple cutting while under tension. This has the sameefiect as sudbetween these rollers is alternately increased or denlyreleasing the tension on a continuous section. Instead of staple cuttingthe cable, the yarns may be stretched until they are broken. In thismethod, by one continuous operation, the yarn bundles coming from thespinning machine are suitably hardened and torn off piece by piece whilebeing stretched to provide staples with an improved curl.

The curl may also be produced on the finished casein yarns which havealready been staple cut, carded and again worked into a ribbon-like orthread-dike product such as webs or slivers and thereafter moistened.

The following specific examples will serve to 11- lustrate severalmethods for carrying out the invention in its preferred form.

Example 1.-The freshly spun, washed, and

to 40% and suddenly relaxed; it is finally staple cut and dried.

Example 2.-'Ihe process is conducted in accordance with Example 1,except that while the cable is in a stretched condition, it is staplecut, the cutting operation having the same efiect as the sudden releaseof tension upon a continuous section oi the cable.

Example 3.The process is conducted in accordance with Example 1, exceptthat the cable is stretched until it is broken piece by piece therebyproviding the necessary stretching, relaxation and staple formation in asingle continuous operation.

Example 4.--In applying the invention to a normally finished product, acarded sliver or web that has been produced from staple cut fibers, ismoistened by immersion or spraying and the like. It is then suddenlystretched either continuously or intermittently, and quickly relaxed andfinally dried under low tension.

It is understood, oi course, that variations may vention and variousdevices may be employed for that purpose without departing from thespirit oi the invention or the scope of the appended claims.

What is claimed is:

1. A process of curling casein fibers which comprises extruding a caseinsolution from a number of spinnerets to form a cable composed of severalfibers, coagulating and hardening the cable in a formaldehyde solution,applying a sudden stretch and while undergoing said stretch, severingsuccessive sections of the cable thereby forming accentuated curlstherein.

2. A process of curling casein fibers which comprises extruding a caseinsolution from a number of spinnerets .to form a cable composed ofseveral fibers, coagulating and hardening the cable in a formaldehydesolution, applying a sudden stretch suflicient to break the successiveportions of the cable into staple lengths thereby to form curls therein.

ANTON LELY.

